Intranets and Extranets
An intranet is a private computer network that uses Internet Protocols to securely share part of an organisation's information with its employees.
An extranet is similar, but the information can also be shared with customers, suppliers or other approved third parties.
Although both can be totally separate from the Internet, it is common for them to be implemented in part using virtual private networks. These use secure protocols to tunnel through the Internet. This can allow authorised users the ability to login from remote sources.
Next: VPN Activity